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From: Johannes Schindelin <>
To: "Matwey V. Kornilov" <>
Subject: Re: rebase preserve-merges: incorrect merge commits
Date: Mon, 8 Jan 2018 14:56:13 +0100 (STD)	[thread overview]
Message-ID: <nycvar.QRO.> (raw)
In-Reply-To: <>

Hi Matwey,

On Mon, 8 Jan 2018, Matwey V. Kornilov wrote:

> I think that rebase preserve-merges algorithm needs further
> improvements. Probably, you already know it.

Yes. preserve-merges is a fundamentally flawed design.

Please have a look here:

Since we are in a feature freeze in preparation for v2.16.0, I will
submit these patch series shortly after v2.16.0 is released.

> As far as I understand the root cause of this that when new merge
> commit is created by rebase it is done simply by git merge
> $new_parents without taking into account any actual state of the
> initial merge commit.

Indeed. preserve-merges does not allow commits to be reordered. (Actually,
it *does* allow it, but then fails to handle it correctly.) We even have
test cases that mark this as "known breakage".

But really, I do not think it is worth trying to fix the broken design.
Better to go with the new recreate-merges. (I am biased, of course,
because I invented recreate-merges. But then, I also invented
preserve-merges, so ...)


  reply	other threads:[~2018-01-08 13:56 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-08 10:24 rebase preserve-merges: incorrect merge commits Matwey V. Kornilov
2018-01-08 13:56 ` Johannes Schindelin [this message]
2018-01-08 14:42   ` Matwey V. Kornilov
2018-01-08 14:46     ` Matwey V. Kornilov
2018-01-08 16:32       ` Johannes Schindelin
2018-01-08 17:24         ` Matwey V. Kornilov
2018-01-08 19:36           ` Johannes Schindelin
2018-01-09  9:49             ` Matwey V. Kornilov
2018-01-09 13:25               ` Johannes Schindelin
2018-01-09 14:19                 ` Matwey V. Kornilov
2018-01-09 16:29                   ` Johannes Schindelin

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